Anti-icing device for aircraft



"0a. 23, 1945. A BER. 2,387,637

ANTI-ICING DEVICE FOR AIRCRAFT Filed Dec. 17, 1942 2 Sheets-Sheet 1 INVENVI'OR Quasi-N ATTORNEY o zs, 1945. L A. BIERLYQ I 2,387,637

ANTI-ICiNG DEVICE FOR AIRCRAFT Filed Dec. 17, 1942 2 Sheets-Sheet 2 V NVENTOR Mal! Patented Oct. 23, 1945 UNITED STATES PATENT 1 OFFICE r ass'mssi DEVI E FOR AIitcRAtr 1 Lester Almon Bierly, Massillon, Ohio Application 'neeeifiber 17, 1942, SerialNo. 469,303

5Claims. (c1. 244*;134)

' relates to idfvic'sfbr preventing aecumulauon .of res on. parts or enema.

.sucn dieing-uni or the. wings or" ether lifting confirm surfaces or an airplane, for example,

s eamy inereas sthe wigiit'diat must be sun'- ported but also changes the. effective contours of the airfoils and thus lessens their aerodynamic w n Devices heretofore have been employed for breaking up and j dislodging the ice. after it has formed on: the surfaces, but such devicesin them-'- selves add substantially-1 tothe weight of thecraft and also change :unfaizorably the "effective con= tours, of. the surfaces Also var'ious'devices. have been proposed for Contact with structural parts is to" Be avoided not only because or its lodal oven-heating of arts, which greatlyreduces the structural strength of aliir'iiir'ium alldi's, for"; example, and is likely to cause warping or 'zauup 'ef parts, but also because ofthe corrosive-effects of the gases.

It has been proposed to employ, as a heattransfer medium, fresh. air forced through the heating system by the impact of the slip-stream of the airplane, or preferably that of its propeller, on the principle of the Pitot tube, with the assistance of a suction grommet through which the air, after giving up heat to the surfaces to be protected, is discharged into the atmosphere. preferably at a relatively low-pressure part of the airfoil surface.

However, it has been found necessary, at excessive expense, and with excessive addition of weight, to provide a very rapid flow of heated air in contact with the inner surface of the shell or skin of an airplane wing, for example, to avoid the insulating effect of stagnant air and to provide adequate replenishment of heat being removed from the outer surface of the wing by the wiping or scrubbing effect of the slip-stream, containing, as it does, moisture having a-high heat-absorbing capacity.

The chief objects of my invention are to provide inexpensively for the necessarily moderate and uniform application of heat to the part required to be protected from ice formation; to make such provision without ohjectionably adding to the weight of the craft; to avoid local or general overheating of parts; and to avoid the above mentionedand ether disadvantages-6r devices 61% the prior art. l i h As airplane wing is chosenfor buriposesnof 11 lustratioh, but. not (if lifriitation, in the accoif'xipanyihg drawings, in which: U a I Fig. 1 is a plan view of. airplane -w i ng. a ssembly equipped with an ant m, device embodyingf my invention ,its prfer red form.

Fig. 2 is a section online 2-} .ofFig. 1;. Fig. 3 is a fragmentary-f rdntelevation of parts of the wing, the skin of the wing beingbroken awayand. one of its-ribs sectioned to show-parts within the wing in elevation.

Fig, 4 is a section on line 44 of Fig; 3;

'Referring to the drawings; which show the deviceappliedto an airplane wing; although the inventionis not limited to airfoils or to airplanes, the skin I of the wing, usually although not necessarily of an aluminum alloy, isprovided with the. usual internal rib-sections II; II in the nose of the wing, and rib-sections'such as that designated I2 in Fig. 2 in the middle section of the wing, these sections being secured to the usual front and r'ear'wing spars [3, I4 which, withithe skin lifthe'wing; define afi 'at leastsubstantially clsed chamber-in the front part of the wingazfia another in the middle part of the wing.

The ribs here shown are of a standard type and without modification provide space for the mounting of devices hereinafter described, which is an advantage in the employment of the invention, but the invention is not limited to any particular type of rib.

Journaled upon forked brackets l5, l5 projecting from the framing, in the forward compartment of the wing, is a hot-air pipe [6 adapted to be rotated, through suitable drive connections, by a motor I1 (Fig. 1). Because of the location of the motor in the airplane chosen for illustration, a similar hot-air pipe Ili similarly journaled and adapted to be driven by a motor Fl is shown for taking care of part of the wing extending from adjacent the motor exhaust to the fuselage of the airplane.

Similar hot-air pipes I8, l9, l8- and I9 similarly mounted and likewise driven by the motors, are shown in the middle compartment of the wing, which needs to be moderately heated to prevent it from icing up, even though the front third of the wing is more subject to ice accumulation than the rest of the wing.

For convenience of mounting the hot-air pipes are shown as journaled in sets of cradle rollers each comprising rollers such as-are shown at 20,

Thus provision is made for rapid flow of hot- 7 air through all of the pipes.

For transferring heat from such air to-the skin of the wing the imprisoned air within the wing is used as a medium, at a lower temperature than that of the air in the pipes. a I .7 For the double function of effectively effect of stagnantairand to provide the, heatreplenishing wiping or scrubbing effect of. air in contact with the inner surface of the wing shell, and of providing effective transfer of heat from the rotating pipes to the imprisoned air, each of the rotating pipes has secured on its outer surface, as by'welding, between its bearings, a circumferential series of longitudinally disposed webs or fins 30, 30, which provide a large amount of metal radiating surface and also act as agitating or centrifugal-blower blades.

Preferably, although not necessarily, their radially outer portions are curved backward'with relation to the direction of'rotation (indicated by the numerous arrows) and. preferably/ although not necessarily, they extend directly lengthwise of the pipes when no need is apparent for circulation of imprisoned air lengthwise of the wing.

Suitable manual or thermostatic controls '(not shownl preferably are provided for controlling the motors and permissibly'alsothe several flow passages."

The mode ofoperatio'n of the device will-be manifest from the foregoing description.

Various modifications are possible without sacrifice of all of the advantages set-out in the above statement of objects and without departure from the scope of the appended claims.

I claim:

1. A device for preventing accumulation of ice upon a hollowaircraft part, said device comprising a pipe rotatably mounted within the part, air-impelling means mounted on the exterior of the pipe in heat-conductive relation thereto, and

pipe." U. 2:"A device for'preventing accumulation of ice upon a hollow aircraft airfoil, said device comprising an elongated member mounted within the airfoil for rotation on its longitudinal axis, said member axially extending substantially throughout the length of the airfoil, air-impeller means mounted onsaid member in heat conductive recirculatlation thereto, and'means for rotating and for ing the imprisoned air, to avoid the insulating heating said member.

3. A device for preventing accumulation of ice upon a hollow aircraft part, said device comprising a pipe rotatably mounted within the part, airimpelling means mounted on the exterior ofthe ipe in heat-conductive relation thereto, means for supplying a heated fluid to the interior of the pipe, and means for rotating the pipe.

4. A device for preventing accumulation of ice upon a hollow aircraft part, said device comprising an elongated membermounted within the part" for rotation 'on its longitudinal axis, airimpeller means mounted'on said member in heatconductive' relation thereto, and means for ro-'- tating and for heating said-'memben'the ai'rim-' peller means comprising a circumferential series of elongated fins disposed 'lengthw'ise of the member.

5. A device for preventing accumulationof ice upon a hollow aircraft part, said device coniprising an elongated/member mounted within the part-for rotation on its longitudinal axis, air-impeller means mounted on said member'in heat-conductive relation thereto; and: means; for rotating and for heating said member, the-said member being journalled at a position betwee two units of the. air-impeller means.

- LESTER. ALMON B1ERLY.--

means for internally heating and f or rotating the 

